Private gardens form an important part of London's landscape and research has shown that gardens are the most popular place for people to enjoy seeing wildlife.

The former London Ecology Unit carried out an analysis of aerial photographs in 1992 and deduced that private gardens comprise approximately 20% of Greater London, equivalent to 31,000 hectares. They are probably the most varied areas of green space in the Capital, ranging in size from the tiny 'pocket handkerchief' backyard in the central London boroughs, to the elaborate, intensively landscaped parkland of London's mansions. The growth of London in the 1920s and 1930s created large areas of low-density housing, often detached or semi-detached properties with front and back gardens of reasonable size.

There needs to be a co-ordinated effort by wildlife groups, horticulturalists, the garden industry and individual gardeners to bring action for gardens together. This habitat statement is the first step towards achieving this, but work will begin on a more detailed Habitat Action Plan in 2001. New partners would be welcomed to help us develop this action.

Wildlife gardening has traditionally been about giving people opportunities to see common wildlife on a day to day basis. Although gardens may not have been recognised as a rich biodiversity resource in the past, this has now changed. Factors such as the loss of farm ponds have given garden ponds an increasing importance for a range of wildlife, such as amphibians and dragonflies. Many gardens have mature trees and provide good breeding habitats for common bird species. Gardens are also undoubtedly important for roosting and feeding bats and a number of mammals, including foxes and hedgehogs, have found gardens to be excellent habitat. Detailed invertebrate surveys of some gardens have found other interesting species, including some rare Red Data Book specimens. A recent survey of Buckingham Palace Garden by the London Natural History Society in 1999 (Supplement to the London Naturalist 1999) demonstrated how gardens can be extremely valuable for a wide range of invertebrates and birds.

The biodiversity value of gardens varies greatly. Size and type of management is a crucial factor and connectivity with adjacent plots provides larger blocks of open land, albeit divided up by fences and walls. Aerial photographs probably best illustrate the value of gardens in terms of open space, with large interconnected areas allowing wildlife to flourish.

The gardening industry's procurement process often sources unsustainable products such as peat, a variety of pesticides and tropical hardwoods. Local demand is often fed by countries on the other side of the world, located at the end of a very long supply chain. Water use is also an issue, both to the horticulture industry growing plants for sale and to gardeners themselves, particularly in times of drought. Alternatives can be found, however, and some suppliers make efforts to minimise their ecological 'footprint'.

Like any piece of land, gardens are subject to planning controls. However, very few are protected from development purely from a biodiversity perspective (there are some private gardens that are part of Sites of Importance for Nature Conservation (SINC) and, in addition, one or two gardens protected as sites themselves). There is pressure for 'backland' development of gardens to meet targets for new housing. An additional trend is the loss of front gardens to off-street parking. Similarly, pressure to build more dense housing within London as a result of a call to halt 'greenfield' development will lead to fewer new gardens of any great size being created.

Change in ownership, and subsequent interest in design and layout can dramatically change an individual garden's value for wildlife. Ponds can be created or filled in, shrubberies planted or removed, and dead wood habitat left or cleared away.

Styles of gardens have changed dramatically over the centuries as fashions come and go. More formal gardens, with the elaborate clipped topiary of early garden design, have given way to naturalistic gardens and what is now a huge array of styles.

Gardening today is one of the biggest leisure pursuits in Britain, and the horticulture industry is a significant factor to the economy. A plethora of garden shows, including Chelsea and Hampton Court attract tens of thousands of people, and there is a wealth of television programmes, books, magazines and articles on the subject.

Wildlife gardening in its own right has become more and more fashionable and has been promoted by the media since the 1980s. Wildlife 'show' gardens at Hampton Court and Regent's Park flower shows have been extremely popular with the public, keen to find out how they can attract wildlife into their gardens.

A number of borough councils have been promoting wildlife gardening to the public, either as part of their Local Agenda 21 programme or as part of their local biodiversity action planning process. The London Borough of Redbridge has printed a wildlife gardening booklet called 'First Steps to a Greener Garden' that is being adapted by the Waltham Forest biodiversity partnership. Several boroughs are aiming to produce Garden Habitat Action Plans.

Wildlife 2000 in south-west London developed wildlife gardening competitions, and there have been successful promotions and campaigns in other boroughs such as Bromley and Southwark. There are also a number of community composting initiatives in place across the Capital.

London Wildlife Trust's Centre for Wildlife Gardening in Peckham was set up in 1989 to provide advice on all aspects of wildlife gardening and provide a source of wild flowers, trees and shrubs. There are a number of demonstration wildlife garden features and the Centre runs education programmes for schools. Since opening, the Centre has attracted many thousands of visitors. The WWT Wetland Centre at Barnes also has a number of wildlife-friendly garden designs to provide inspiration to visitors.

In 1999, the London Wildlife Trust, with the help of the London Ecology Unit, developed a simple garden biodiversity survey using a small number of indicator species. This has resulted in over 3,500 survey forms completed for London's gardens and is designed to be able to be repeatable in order to track changes in the overall biodiversity resource. The survey is now running on the Trust's web-site and the results have been plotted onto a Geographical Information System (GIS). Similar surveys have been run by Local Authorities and it is likely that more will take place through the biodiversity action planning process.

Some garden centres, where most gardeners seek advice on gardening, provide limited advice on garden wildlife by labelling plants that are beneficial to wildlife. Wildlife garden products such as nesting boxes and bird tables are often for sale.

Linked to this is the need for greater knowledge into what gardening techniques and features provide the best results in supporting a variety of biodiversity. As well as developing demonstration gardens and assessing garden plants for their wildlife value, this could also involve working with the whole horticulture industry: from garden centres to plant suppliers, to professional garden designers and constructors.